Is there a way to restart a modified addon?
You can go to the Main menu &gt; Blender &gt; System &gt; Reload Scripts. As the name suggests, the operator reloads all addons and scripts, running addons, unregister and register functions.

Another way is hitting F3 and typing &quot;Reload Scripts&quot; in the Operator Search menu and execute the operator. In versions pre Blender 2.8x you can just hit F8 in order to reload.